ModContainer.java

package com.yolp900.itsjustacharm.common.inventory;

import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.inventory.Container;
import net.minecraft.inventory.Slot;
import net.minecraft.item.ItemStack;

public abstract class ModContainer extends Container {

	@Override
	public abstract ItemStack transferStackInSlot(EntityPlayer player, int clickedSlotNumber);

	@Override
	protected boolean mergeItemStack(ItemStack stack, int startIndex, int endIndex, boolean useEndIndex) {
		boolean ret = mergeItemStackRefill(stack, startIndex, endIndex, useEndIndex);
		if (stack != null && stack.stackSize > 0) {
			ret |= mergeItemStackMove(stack, startIndex, endIndex, useEndIndex);
		}
		return ret;
	}

	private boolean mergeItemStackRefill(ItemStack stack, int startIndex, int endIndex, boolean useEndIndex) {
		if (stack.stackSize <= 0) {
			return false;
		}

		boolean flag1 = false;
		int k = startIndex;

		if (useEndIndex) {
			k = endIndex - 1;
		}

		Slot slot;
		ItemStack itemstack1;

		if (stack.isStackable()) {
			while (stack.stackSize > 0 && (!useEndIndex && k < endIndex || useEndIndex && k >= startIndex)) {
				slot = this.inventorySlots.get(k);
				itemstack1 = slot.getStack();

				if (itemstack1 != null
						&& itemstack1.getItem() == stack.getItem()
						&& (!stack.getHasSubtypes() || stack.getMetadata() == itemstack1.getMetadata())
						&& ItemStack.areItemStackTagsEqual(stack, itemstack1)
						&& this.canMergeSlot(stack, slot)) {
					int l = itemstack1.stackSize + stack.stackSize;
					int limit = Math.min(stack.getMaxStackSize(), slot.getItemStackLimit(stack));

					if (l <= limit) {
						stack.stackSize = 0;
						itemstack1.stackSize = l;
						slot.onSlotChanged();
						flag1 = true;
					} else if (itemstack1.stackSize < limit) {
						stack.stackSize -= limit - itemstack1.stackSize;
						itemstack1.stackSize = limit;
						slot.onSlotChanged();
						flag1 = true;
					}
				}

				if (useEndIndex) {
					--k;
				} else {
					++k;
				}
			}
		}

		return flag1;
	}

	private boolean mergeItemStackMove(ItemStack stack, int startIndex, int endIndex, boolean useEndIndex) {
		if (stack.stackSize <= 0) {
			return false;
		}

		boolean flag1 = false;
		int k;

		if (useEndIndex) {
			k = endIndex - 1;
		} else {
			k = startIndex;
		}

		while (!useEndIndex && k < endIndex || useEndIndex && k >= startIndex) {
			Slot slot = this.inventorySlots.get(k);
			ItemStack itemstack1 = slot.getStack();

			if (itemstack1 == null && slot.isItemValid(stack) && this.canMergeSlot(stack, slot)) // Forge: Make sure to respect isItemValid in the slot.
			{
				int limit = slot.getItemStackLimit(stack);
				ItemStack stack2 = stack.copy();
				if (stack2.stackSize > limit) {
					stack2.stackSize = limit;
					stack.stackSize -= limit;
				} else {
					stack.stackSize = 0;
				}
				slot.putStack(stack2);
				slot.onSlotChanged();
				flag1 = true;

				if (stack.stackSize == 0) {
					break;
				}
			}

			if (useEndIndex) {
				--k;
			} else {
				++k;
			}
		}


		return flag1;
	}

	@Override
	public abstract boolean canInteractWith(EntityPlayer player);

}